1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * S390 kdump implementation
4  *
5  * Copyright IBM Corp. 2011
6  * Author(s): Michael Holzheu <holzheu@linux.vnet.ibm.com>
7  */
8 
9 #include <linux/crash_dump.h>
10 #include <asm/lowcore.h>
11 #include <linux/kernel.h>
12 #include <linux/init.h>
13 #include <linux/mm.h>
14 #include <linux/gfp.h>
15 #include <linux/slab.h>
16 #include <linux/memblock.h>
17 #include <linux/elf.h>
18 #include <linux/uio.h>
19 #include <asm/asm-offsets.h>
20 #include <asm/os_info.h>
21 #include <asm/elf.h>
22 #include <asm/ipl.h>
23 #include <asm/sclp.h>
24 #include <asm/maccess.h>
25 
26 #define PTR_ADD(x, y) (((char *) (x)) + ((unsigned long) (y)))
27 #define PTR_SUB(x, y) (((char *) (x)) - ((unsigned long) (y)))
28 #define PTR_DIFF(x, y) ((unsigned long)(((char *) (x)) - ((unsigned long) (y))))
29 
30 static struct memblock_region oldmem_region;
31 
32 static struct memblock_type oldmem_type = {
33 	.cnt = 1,
34 	.max = 1,
35 	.total_size = 0,
36 	.regions = &oldmem_region,
37 	.name = "oldmem",
38 };
39 
40 struct save_area {
41 	struct list_head list;
42 	u64 psw[2];
43 	u64 ctrs[16];
44 	u64 gprs[16];
45 	u32 acrs[16];
46 	u64 fprs[16];
47 	u32 fpc;
48 	u32 prefix;
49 	u32 todpreg;
50 	u64 timer;
51 	u64 todcmp;
52 	u64 vxrs_low[16];
53 	__vector128 vxrs_high[16];
54 };
55 
56 static LIST_HEAD(dump_save_areas);
57 
58 /*
59  * Allocate a save area
60  */
save_area_alloc(bool is_boot_cpu)61 struct save_area * __init save_area_alloc(bool is_boot_cpu)
62 {
63 	struct save_area *sa;
64 
65 	sa = memblock_alloc(sizeof(*sa), 8);
66 	if (!sa)
67 		return NULL;
68 
69 	if (is_boot_cpu)
70 		list_add(&sa->list, &dump_save_areas);
71 	else
72 		list_add_tail(&sa->list, &dump_save_areas);
73 	return sa;
74 }
75 
76 /*
77  * Return the address of the save area for the boot CPU
78  */
save_area_boot_cpu(void)79 struct save_area * __init save_area_boot_cpu(void)
80 {
81 	return list_first_entry_or_null(&dump_save_areas, struct save_area, list);
82 }
83 
84 /*
85  * Copy CPU registers into the save area
86  */
save_area_add_regs(struct save_area * sa,void * regs)87 void __init save_area_add_regs(struct save_area *sa, void *regs)
88 {
89 	struct lowcore *lc;
90 
91 	lc = (struct lowcore *)(regs - __LC_FPREGS_SAVE_AREA);
92 	memcpy(&sa->psw, &lc->psw_save_area, sizeof(sa->psw));
93 	memcpy(&sa->ctrs, &lc->cregs_save_area, sizeof(sa->ctrs));
94 	memcpy(&sa->gprs, &lc->gpregs_save_area, sizeof(sa->gprs));
95 	memcpy(&sa->acrs, &lc->access_regs_save_area, sizeof(sa->acrs));
96 	memcpy(&sa->fprs, &lc->floating_pt_save_area, sizeof(sa->fprs));
97 	memcpy(&sa->fpc, &lc->fpt_creg_save_area, sizeof(sa->fpc));
98 	memcpy(&sa->prefix, &lc->prefixreg_save_area, sizeof(sa->prefix));
99 	memcpy(&sa->todpreg, &lc->tod_progreg_save_area, sizeof(sa->todpreg));
100 	memcpy(&sa->timer, &lc->cpu_timer_save_area, sizeof(sa->timer));
101 	memcpy(&sa->todcmp, &lc->clock_comp_save_area, sizeof(sa->todcmp));
102 }
103 
104 /*
105  * Copy vector registers into the save area
106  */
save_area_add_vxrs(struct save_area * sa,__vector128 * vxrs)107 void __init save_area_add_vxrs(struct save_area *sa, __vector128 *vxrs)
108 {
109 	int i;
110 
111 	/* Copy lower halves of vector registers 0-15 */
112 	for (i = 0; i < 16; i++)
113 		memcpy(&sa->vxrs_low[i], &vxrs[i].u[2], 8);
114 	/* Copy vector registers 16-31 */
115 	memcpy(sa->vxrs_high, vxrs + 16, 16 * sizeof(__vector128));
116 }
117 
copy_oldmem_iter(struct iov_iter * iter,unsigned long src,size_t count)118 static size_t copy_oldmem_iter(struct iov_iter *iter, unsigned long src, size_t count)
119 {
120 	size_t len, copied, res = 0;
121 
122 	while (count) {
123 		if (!oldmem_data.start && src < sclp.hsa_size) {
124 			/* Copy from zfcp/nvme dump HSA area */
125 			len = min(count, sclp.hsa_size - src);
126 			copied = memcpy_hsa_iter(iter, src, len);
127 		} else {
128 			/* Check for swapped kdump oldmem areas */
129 			if (oldmem_data.start && src - oldmem_data.start < oldmem_data.size) {
130 				src -= oldmem_data.start;
131 				len = min(count, oldmem_data.size - src);
132 			} else if (oldmem_data.start && src < oldmem_data.size) {
133 				len = min(count, oldmem_data.size - src);
134 				src += oldmem_data.start;
135 			} else {
136 				len = count;
137 			}
138 			copied = memcpy_real_iter(iter, src, len);
139 		}
140 		count -= copied;
141 		src += copied;
142 		res += copied;
143 		if (copied < len)
144 			break;
145 	}
146 	return res;
147 }
148 
copy_oldmem_kernel(void * dst,unsigned long src,size_t count)149 int copy_oldmem_kernel(void *dst, unsigned long src, size_t count)
150 {
151 	struct iov_iter iter;
152 	struct kvec kvec;
153 
154 	kvec.iov_base = dst;
155 	kvec.iov_len = count;
156 	iov_iter_kvec(&iter, WRITE, &kvec, 1, count);
157 	if (copy_oldmem_iter(&iter, src, count) < count)
158 		return -EFAULT;
159 	return 0;
160 }
161 
162 /*
163  * Copy one page from "oldmem"
164  */
copy_oldmem_page(struct iov_iter * iter,unsigned long pfn,size_t csize,unsigned long offset)165 ssize_t copy_oldmem_page(struct iov_iter *iter, unsigned long pfn, size_t csize,
166 			 unsigned long offset)
167 {
168 	unsigned long src;
169 
170 	src = pfn_to_phys(pfn) + offset;
171 	return copy_oldmem_iter(iter, src, csize);
172 }
173 
174 /*
175  * Remap "oldmem" for kdump
176  *
177  * For the kdump reserved memory this functions performs a swap operation:
178  * [0 - OLDMEM_SIZE] is mapped to [OLDMEM_BASE - OLDMEM_BASE + OLDMEM_SIZE]
179  */
remap_oldmem_pfn_range_kdump(struct vm_area_struct * vma,unsigned long from,unsigned long pfn,unsigned long size,pgprot_t prot)180 static int remap_oldmem_pfn_range_kdump(struct vm_area_struct *vma,
181 					unsigned long from, unsigned long pfn,
182 					unsigned long size, pgprot_t prot)
183 {
184 	unsigned long size_old;
185 	int rc;
186 
187 	if (pfn < oldmem_data.size >> PAGE_SHIFT) {
188 		size_old = min(size, oldmem_data.size - (pfn << PAGE_SHIFT));
189 		rc = remap_pfn_range(vma, from,
190 				     pfn + (oldmem_data.start >> PAGE_SHIFT),
191 				     size_old, prot);
192 		if (rc || size == size_old)
193 			return rc;
194 		size -= size_old;
195 		from += size_old;
196 		pfn += size_old >> PAGE_SHIFT;
197 	}
198 	return remap_pfn_range(vma, from, pfn, size, prot);
199 }
200 
201 /*
202  * Remap "oldmem" for zfcp/nvme dump
203  *
204  * We only map available memory above HSA size. Memory below HSA size
205  * is read on demand using the copy_oldmem_page() function.
206  */
remap_oldmem_pfn_range_zfcpdump(struct vm_area_struct * vma,unsigned long from,unsigned long pfn,unsigned long size,pgprot_t prot)207 static int remap_oldmem_pfn_range_zfcpdump(struct vm_area_struct *vma,
208 					   unsigned long from,
209 					   unsigned long pfn,
210 					   unsigned long size, pgprot_t prot)
211 {
212 	unsigned long hsa_end = sclp.hsa_size;
213 	unsigned long size_hsa;
214 
215 	if (pfn < hsa_end >> PAGE_SHIFT) {
216 		size_hsa = min(size, hsa_end - (pfn << PAGE_SHIFT));
217 		if (size == size_hsa)
218 			return 0;
219 		size -= size_hsa;
220 		from += size_hsa;
221 		pfn += size_hsa >> PAGE_SHIFT;
222 	}
223 	return remap_pfn_range(vma, from, pfn, size, prot);
224 }
225 
226 /*
227  * Remap "oldmem" for kdump or zfcp/nvme dump
228  */
remap_oldmem_pfn_range(struct vm_area_struct * vma,unsigned long from,unsigned long pfn,unsigned long size,pgprot_t prot)229 int remap_oldmem_pfn_range(struct vm_area_struct *vma, unsigned long from,
230 			   unsigned long pfn, unsigned long size, pgprot_t prot)
231 {
232 	if (oldmem_data.start)
233 		return remap_oldmem_pfn_range_kdump(vma, from, pfn, size, prot);
234 	else
235 		return remap_oldmem_pfn_range_zfcpdump(vma, from, pfn, size,
236 						       prot);
237 }
238 
nt_name(Elf64_Word type)239 static const char *nt_name(Elf64_Word type)
240 {
241 	const char *name = "LINUX";
242 
243 	if (type == NT_PRPSINFO || type == NT_PRSTATUS || type == NT_PRFPREG)
244 		name = KEXEC_CORE_NOTE_NAME;
245 	return name;
246 }
247 
248 /*
249  * Initialize ELF note
250  */
nt_init_name(void * buf,Elf64_Word type,void * desc,int d_len,const char * name)251 static void *nt_init_name(void *buf, Elf64_Word type, void *desc, int d_len,
252 			  const char *name)
253 {
254 	Elf64_Nhdr *note;
255 	u64 len;
256 
257 	note = (Elf64_Nhdr *)buf;
258 	note->n_namesz = strlen(name) + 1;
259 	note->n_descsz = d_len;
260 	note->n_type = type;
261 	len = sizeof(Elf64_Nhdr);
262 
263 	memcpy(buf + len, name, note->n_namesz);
264 	len = roundup(len + note->n_namesz, 4);
265 
266 	memcpy(buf + len, desc, note->n_descsz);
267 	len = roundup(len + note->n_descsz, 4);
268 
269 	return PTR_ADD(buf, len);
270 }
271 
nt_init(void * buf,Elf64_Word type,void * desc,int d_len)272 static inline void *nt_init(void *buf, Elf64_Word type, void *desc, int d_len)
273 {
274 	return nt_init_name(buf, type, desc, d_len, nt_name(type));
275 }
276 
277 /*
278  * Calculate the size of ELF note
279  */
nt_size_name(int d_len,const char * name)280 static size_t nt_size_name(int d_len, const char *name)
281 {
282 	size_t size;
283 
284 	size = sizeof(Elf64_Nhdr);
285 	size += roundup(strlen(name) + 1, 4);
286 	size += roundup(d_len, 4);
287 
288 	return size;
289 }
290 
nt_size(Elf64_Word type,int d_len)291 static inline size_t nt_size(Elf64_Word type, int d_len)
292 {
293 	return nt_size_name(d_len, nt_name(type));
294 }
295 
296 /*
297  * Fill ELF notes for one CPU with save area registers
298  */
fill_cpu_elf_notes(void * ptr,int cpu,struct save_area * sa)299 static void *fill_cpu_elf_notes(void *ptr, int cpu, struct save_area *sa)
300 {
301 	struct elf_prstatus nt_prstatus;
302 	elf_fpregset_t nt_fpregset;
303 
304 	/* Prepare prstatus note */
305 	memset(&nt_prstatus, 0, sizeof(nt_prstatus));
306 	memcpy(&nt_prstatus.pr_reg.gprs, sa->gprs, sizeof(sa->gprs));
307 	memcpy(&nt_prstatus.pr_reg.psw, sa->psw, sizeof(sa->psw));
308 	memcpy(&nt_prstatus.pr_reg.acrs, sa->acrs, sizeof(sa->acrs));
309 	nt_prstatus.common.pr_pid = cpu;
310 	/* Prepare fpregset (floating point) note */
311 	memset(&nt_fpregset, 0, sizeof(nt_fpregset));
312 	memcpy(&nt_fpregset.fpc, &sa->fpc, sizeof(sa->fpc));
313 	memcpy(&nt_fpregset.fprs, &sa->fprs, sizeof(sa->fprs));
314 	/* Create ELF notes for the CPU */
315 	ptr = nt_init(ptr, NT_PRSTATUS, &nt_prstatus, sizeof(nt_prstatus));
316 	ptr = nt_init(ptr, NT_PRFPREG, &nt_fpregset, sizeof(nt_fpregset));
317 	ptr = nt_init(ptr, NT_S390_TIMER, &sa->timer, sizeof(sa->timer));
318 	ptr = nt_init(ptr, NT_S390_TODCMP, &sa->todcmp, sizeof(sa->todcmp));
319 	ptr = nt_init(ptr, NT_S390_TODPREG, &sa->todpreg, sizeof(sa->todpreg));
320 	ptr = nt_init(ptr, NT_S390_CTRS, &sa->ctrs, sizeof(sa->ctrs));
321 	ptr = nt_init(ptr, NT_S390_PREFIX, &sa->prefix, sizeof(sa->prefix));
322 	if (MACHINE_HAS_VX) {
323 		ptr = nt_init(ptr, NT_S390_VXRS_HIGH,
324 			      &sa->vxrs_high, sizeof(sa->vxrs_high));
325 		ptr = nt_init(ptr, NT_S390_VXRS_LOW,
326 			      &sa->vxrs_low, sizeof(sa->vxrs_low));
327 	}
328 	return ptr;
329 }
330 
331 /*
332  * Calculate size of ELF notes per cpu
333  */
get_cpu_elf_notes_size(void)334 static size_t get_cpu_elf_notes_size(void)
335 {
336 	struct save_area *sa = NULL;
337 	size_t size;
338 
339 	size =	nt_size(NT_PRSTATUS, sizeof(struct elf_prstatus));
340 	size +=  nt_size(NT_PRFPREG, sizeof(elf_fpregset_t));
341 	size +=  nt_size(NT_S390_TIMER, sizeof(sa->timer));
342 	size +=  nt_size(NT_S390_TODCMP, sizeof(sa->todcmp));
343 	size +=  nt_size(NT_S390_TODPREG, sizeof(sa->todpreg));
344 	size +=  nt_size(NT_S390_CTRS, sizeof(sa->ctrs));
345 	size +=  nt_size(NT_S390_PREFIX, sizeof(sa->prefix));
346 	if (MACHINE_HAS_VX) {
347 		size += nt_size(NT_S390_VXRS_HIGH, sizeof(sa->vxrs_high));
348 		size += nt_size(NT_S390_VXRS_LOW, sizeof(sa->vxrs_low));
349 	}
350 
351 	return size;
352 }
353 
354 /*
355  * Initialize prpsinfo note (new kernel)
356  */
nt_prpsinfo(void * ptr)357 static void *nt_prpsinfo(void *ptr)
358 {
359 	struct elf_prpsinfo prpsinfo;
360 
361 	memset(&prpsinfo, 0, sizeof(prpsinfo));
362 	prpsinfo.pr_sname = 'R';
363 	strcpy(prpsinfo.pr_fname, "vmlinux");
364 	return nt_init(ptr, NT_PRPSINFO, &prpsinfo, sizeof(prpsinfo));
365 }
366 
367 /*
368  * Get vmcoreinfo using lowcore->vmcore_info (new kernel)
369  */
get_vmcoreinfo_old(unsigned long * size)370 static void *get_vmcoreinfo_old(unsigned long *size)
371 {
372 	char nt_name[11], *vmcoreinfo;
373 	unsigned long addr;
374 	Elf64_Nhdr note;
375 
376 	if (copy_oldmem_kernel(&addr, __LC_VMCORE_INFO, sizeof(addr)))
377 		return NULL;
378 	memset(nt_name, 0, sizeof(nt_name));
379 	if (copy_oldmem_kernel(&note, addr, sizeof(note)))
380 		return NULL;
381 	if (copy_oldmem_kernel(nt_name, addr + sizeof(note),
382 			       sizeof(nt_name) - 1))
383 		return NULL;
384 	if (strcmp(nt_name, VMCOREINFO_NOTE_NAME) != 0)
385 		return NULL;
386 	vmcoreinfo = kzalloc(note.n_descsz, GFP_KERNEL);
387 	if (!vmcoreinfo)
388 		return NULL;
389 	if (copy_oldmem_kernel(vmcoreinfo, addr + 24, note.n_descsz)) {
390 		kfree(vmcoreinfo);
391 		return NULL;
392 	}
393 	*size = note.n_descsz;
394 	return vmcoreinfo;
395 }
396 
397 /*
398  * Initialize vmcoreinfo note (new kernel)
399  */
nt_vmcoreinfo(void * ptr)400 static void *nt_vmcoreinfo(void *ptr)
401 {
402 	const char *name = VMCOREINFO_NOTE_NAME;
403 	unsigned long size;
404 	void *vmcoreinfo;
405 
406 	vmcoreinfo = os_info_old_entry(OS_INFO_VMCOREINFO, &size);
407 	if (vmcoreinfo)
408 		return nt_init_name(ptr, 0, vmcoreinfo, size, name);
409 
410 	vmcoreinfo = get_vmcoreinfo_old(&size);
411 	if (!vmcoreinfo)
412 		return ptr;
413 	ptr = nt_init_name(ptr, 0, vmcoreinfo, size, name);
414 	kfree(vmcoreinfo);
415 	return ptr;
416 }
417 
nt_vmcoreinfo_size(void)418 static size_t nt_vmcoreinfo_size(void)
419 {
420 	const char *name = VMCOREINFO_NOTE_NAME;
421 	unsigned long size;
422 	void *vmcoreinfo;
423 
424 	vmcoreinfo = os_info_old_entry(OS_INFO_VMCOREINFO, &size);
425 	if (vmcoreinfo)
426 		return nt_size_name(size, name);
427 
428 	vmcoreinfo = get_vmcoreinfo_old(&size);
429 	if (!vmcoreinfo)
430 		return 0;
431 
432 	kfree(vmcoreinfo);
433 	return nt_size_name(size, name);
434 }
435 
436 /*
437  * Initialize final note (needed for /proc/vmcore code)
438  */
nt_final(void * ptr)439 static void *nt_final(void *ptr)
440 {
441 	Elf64_Nhdr *note;
442 
443 	note = (Elf64_Nhdr *) ptr;
444 	note->n_namesz = 0;
445 	note->n_descsz = 0;
446 	note->n_type = 0;
447 	return PTR_ADD(ptr, sizeof(Elf64_Nhdr));
448 }
449 
450 /*
451  * Initialize ELF header (new kernel)
452  */
ehdr_init(Elf64_Ehdr * ehdr,int mem_chunk_cnt)453 static void *ehdr_init(Elf64_Ehdr *ehdr, int mem_chunk_cnt)
454 {
455 	memset(ehdr, 0, sizeof(*ehdr));
456 	memcpy(ehdr->e_ident, ELFMAG, SELFMAG);
457 	ehdr->e_ident[EI_CLASS] = ELFCLASS64;
458 	ehdr->e_ident[EI_DATA] = ELFDATA2MSB;
459 	ehdr->e_ident[EI_VERSION] = EV_CURRENT;
460 	memset(ehdr->e_ident + EI_PAD, 0, EI_NIDENT - EI_PAD);
461 	ehdr->e_type = ET_CORE;
462 	ehdr->e_machine = EM_S390;
463 	ehdr->e_version = EV_CURRENT;
464 	ehdr->e_phoff = sizeof(Elf64_Ehdr);
465 	ehdr->e_ehsize = sizeof(Elf64_Ehdr);
466 	ehdr->e_phentsize = sizeof(Elf64_Phdr);
467 	ehdr->e_phnum = mem_chunk_cnt + 1;
468 	return ehdr + 1;
469 }
470 
471 /*
472  * Return CPU count for ELF header (new kernel)
473  */
get_cpu_cnt(void)474 static int get_cpu_cnt(void)
475 {
476 	struct save_area *sa;
477 	int cpus = 0;
478 
479 	list_for_each_entry(sa, &dump_save_areas, list)
480 		if (sa->prefix != 0)
481 			cpus++;
482 	return cpus;
483 }
484 
485 /*
486  * Return memory chunk count for ELF header (new kernel)
487  */
get_mem_chunk_cnt(void)488 static int get_mem_chunk_cnt(void)
489 {
490 	int cnt = 0;
491 	u64 idx;
492 
493 	for_each_physmem_range(idx, &oldmem_type, NULL, NULL)
494 		cnt++;
495 	return cnt;
496 }
497 
498 /*
499  * Initialize ELF loads (new kernel)
500  */
loads_init(Elf64_Phdr * phdr,u64 loads_offset)501 static void loads_init(Elf64_Phdr *phdr, u64 loads_offset)
502 {
503 	phys_addr_t start, end;
504 	u64 idx;
505 
506 	for_each_physmem_range(idx, &oldmem_type, &start, &end) {
507 		phdr->p_filesz = end - start;
508 		phdr->p_type = PT_LOAD;
509 		phdr->p_offset = start;
510 		phdr->p_vaddr = start;
511 		phdr->p_paddr = start;
512 		phdr->p_memsz = end - start;
513 		phdr->p_flags = PF_R | PF_W | PF_X;
514 		phdr->p_align = PAGE_SIZE;
515 		phdr++;
516 	}
517 }
518 
519 /*
520  * Initialize notes (new kernel)
521  */
notes_init(Elf64_Phdr * phdr,void * ptr,u64 notes_offset)522 static void *notes_init(Elf64_Phdr *phdr, void *ptr, u64 notes_offset)
523 {
524 	struct save_area *sa;
525 	void *ptr_start = ptr;
526 	int cpu;
527 
528 	ptr = nt_prpsinfo(ptr);
529 
530 	cpu = 1;
531 	list_for_each_entry(sa, &dump_save_areas, list)
532 		if (sa->prefix != 0)
533 			ptr = fill_cpu_elf_notes(ptr, cpu++, sa);
534 	ptr = nt_vmcoreinfo(ptr);
535 	ptr = nt_final(ptr);
536 	memset(phdr, 0, sizeof(*phdr));
537 	phdr->p_type = PT_NOTE;
538 	phdr->p_offset = notes_offset;
539 	phdr->p_filesz = (unsigned long) PTR_SUB(ptr, ptr_start);
540 	phdr->p_memsz = phdr->p_filesz;
541 	return ptr;
542 }
543 
get_elfcorehdr_size(int mem_chunk_cnt)544 static size_t get_elfcorehdr_size(int mem_chunk_cnt)
545 {
546 	size_t size;
547 
548 	size = sizeof(Elf64_Ehdr);
549 	/* PT_NOTES */
550 	size += sizeof(Elf64_Phdr);
551 	/* nt_prpsinfo */
552 	size += nt_size(NT_PRPSINFO, sizeof(struct elf_prpsinfo));
553 	/* regsets */
554 	size += get_cpu_cnt() * get_cpu_elf_notes_size();
555 	/* nt_vmcoreinfo */
556 	size += nt_vmcoreinfo_size();
557 	/* nt_final */
558 	size += sizeof(Elf64_Nhdr);
559 	/* PT_LOADS */
560 	size += mem_chunk_cnt * sizeof(Elf64_Phdr);
561 
562 	return size;
563 }
564 
565 /*
566  * Create ELF core header (new kernel)
567  */
elfcorehdr_alloc(unsigned long long * addr,unsigned long long * size)568 int elfcorehdr_alloc(unsigned long long *addr, unsigned long long *size)
569 {
570 	Elf64_Phdr *phdr_notes, *phdr_loads;
571 	int mem_chunk_cnt;
572 	void *ptr, *hdr;
573 	u32 alloc_size;
574 	u64 hdr_off;
575 
576 	/* If we are not in kdump or zfcp/nvme dump mode return */
577 	if (!oldmem_data.start && !is_ipl_type_dump())
578 		return 0;
579 	/* If we cannot get HSA size for zfcp/nvme dump return error */
580 	if (is_ipl_type_dump() && !sclp.hsa_size)
581 		return -ENODEV;
582 
583 	/* For kdump, exclude previous crashkernel memory */
584 	if (oldmem_data.start) {
585 		oldmem_region.base = oldmem_data.start;
586 		oldmem_region.size = oldmem_data.size;
587 		oldmem_type.total_size = oldmem_data.size;
588 	}
589 
590 	mem_chunk_cnt = get_mem_chunk_cnt();
591 
592 	alloc_size = get_elfcorehdr_size(mem_chunk_cnt);
593 
594 	hdr = kzalloc(alloc_size, GFP_KERNEL);
595 
596 	/* Without elfcorehdr /proc/vmcore cannot be created. Thus creating
597 	 * a dump with this crash kernel will fail. Panic now to allow other
598 	 * dump mechanisms to take over.
599 	 */
600 	if (!hdr)
601 		panic("s390 kdump allocating elfcorehdr failed");
602 
603 	/* Init elf header */
604 	ptr = ehdr_init(hdr, mem_chunk_cnt);
605 	/* Init program headers */
606 	phdr_notes = ptr;
607 	ptr = PTR_ADD(ptr, sizeof(Elf64_Phdr));
608 	phdr_loads = ptr;
609 	ptr = PTR_ADD(ptr, sizeof(Elf64_Phdr) * mem_chunk_cnt);
610 	/* Init notes */
611 	hdr_off = PTR_DIFF(ptr, hdr);
612 	ptr = notes_init(phdr_notes, ptr, ((unsigned long) hdr) + hdr_off);
613 	/* Init loads */
614 	hdr_off = PTR_DIFF(ptr, hdr);
615 	loads_init(phdr_loads, hdr_off);
616 	*addr = (unsigned long long) hdr;
617 	*size = (unsigned long long) hdr_off;
618 	BUG_ON(elfcorehdr_size > alloc_size);
619 	return 0;
620 }
621 
622 /*
623  * Free ELF core header (new kernel)
624  */
elfcorehdr_free(unsigned long long addr)625 void elfcorehdr_free(unsigned long long addr)
626 {
627 	kfree((void *)(unsigned long)addr);
628 }
629 
630 /*
631  * Read from ELF header
632  */
elfcorehdr_read(char * buf,size_t count,u64 * ppos)633 ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos)
634 {
635 	void *src = (void *)(unsigned long)*ppos;
636 
637 	memcpy(buf, src, count);
638 	*ppos += count;
639 	return count;
640 }
641 
642 /*
643  * Read from ELF notes data
644  */
elfcorehdr_read_notes(char * buf,size_t count,u64 * ppos)645 ssize_t elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos)
646 {
647 	void *src = (void *)(unsigned long)*ppos;
648 
649 	memcpy(buf, src, count);
650 	*ppos += count;
651 	return count;
652 }
653